Feature: Lazy loading of poster images

[pushmatrix]

already have lazy loading of 3D models in (which is awesome). It'd be nice to piggyback on that functionality and make the poster lazyload as well. Especially since posters don't have srcset support for multiple resolutions, it can take a lot of bandwidth if posters are big.

[cdata]

In general I agree and I think we will support this via the poster attribute.

That said, I'm interested to know: do you think you could address this case with something like <img srcset="..." loading="lazy">?

[pushmatrix]

Are you suggesting that it would be done through slots for poster?

[cdata]

@pushmatrix yah, something along the lines of:

<model-viewer>
  <img srcset="..." loading="lazy" slot="poster">
</model-viewer>

Obligatory caveat: loading attribute is only available in Chrome at this time.

[pushmatrix]

If we did that slot thing, would it break any of the css stuff that @elalish did for seamless poster transitions?

[elalish]

@pushmatrix No, if you use the same poster image and set background-size: contain, background-repeat: no-repeat, and background-position: center, it should work just fine.